This invention relates to an apparatus and method for detecting and discriminating articles that are within a predetermined range of a specification into lots. More particularly, this invention relates to an apparatus and method for detecting and discriminating articles that have been separated and singulated while being conveyed to the apparatus of the present invention, and a system and method for simultaneous high speed processing of articles. The specification could be volume, individual or total, of articles; size or other physical characteristic of the articles; count of articles; or combinations of these properties.
Devices for counting or aggregating articles are known. For example, U.S. Pat. Nos. 5,313,508 and 5,454,016, which are incorporated herein by reference in their entireties, disclose methods and apparatus for counting irregularly shaped articles. A pair of alternately energized light sources is provided at a sensing plane through which articles to be counted pass. Each of the light sources emits a light beam that is at an angle to the other light beam, such as an angle of about 90°.
U.S. Pat. No. 6,836,527 B1, also incorporated herein by reference in its entirety, further improves on the foregoing methods and apparatus for counting articles by providing reliable counting of unsymmetrical articles by volume or partial volume, using three-dimensional imaging of the articles as they traverse the light beams and sensors of the apparatus. This latter apparatus and method also allows for sensing of the most efficient throughput counting speed for the particular articles being counted, enabling feedback adjustment of article feed rates into the apparatus.
U.S. Pat. No. 5,804,772, which is incorporated herein by reference in its entirety, discloses an apparatus and method for aggregating a desired number of articles without individually counting out each article to achieve the desired number. A stream of the articles is discharged into a weigh hopper until substantially a predetermined weight of articles is in the hopper. The number of articles in the hopper is determined from the total weight of the hopper and the weight of a single article.
U.S. Pat. No. 6,360,870, which is incorporated herein by reference in its entirety, discloses an apparatus which comprises a plurality of outlets radiating outwardly from the periphery of a feeder bowl. The number of outlets can be as few as two with no upper limit except as dictated by physical constraints. It is possible that as many as about 100 could be used depending on bowl size and/or diameter, and track size. Specifically, the device has multiple tracks spiraling or radially exiting out from a center cone or other structure. The tracks all have tooling designed to shed bulk loose product down to single file feed, exiting product in controlled flow from the bowl around the entire periphery at the end of each track. The bowl passes the excess overflow via an integral catch pan that provides a path for the bulk excess product to exit the bowl feeder from underneath the multiple tracks for a return run through the multi-track feeder. At each exit, an optical parts detector, laser, light beam, load cell, or similar type device, with a product diverter gate, and an accumulator with discharge gates, is positioned to count, weigh, apportion by volume, discriminate by some other characteristic of the articles, or some combination of these properties, the loose product into the desired batch size or volume. These detectors may combine their counts for large batch sizes, or each be individually programmed to count each total batch or any combination of these optical batches and weighed batches satisfying their requested batch size or volume.
In another aspect of the invention of the aforementioned U.S. Pat. No. 6,360,870, a bowl configuration is provided for bulk product distribution that can deliver product uniformly and/or oriented in a controlled fashion out its entire periphery overflowing out of itself evenly and smoothly around a 360 degree circle. This bowl is designed to receive bulk product from bucket conveyors, bin vibratory elevators, and/or other similar delivery means. This device by nature of its design shape will collect the product in the bottom center of a cone, bowl or other similar shaped device. The bowl has spiral vanes, tracks, diverters, or other similar devices affixed to its interior surfaces that will guide and encourage the product to climb out of and spread itself evenly and uniformly out of the periphery of the device.
U.S. Pat. No. 6,563,901 B2, which is incorporated herein by reference in its entirety, discloses a multi-head counting system in which a counter unit counts discrete articles within a predetermined size range into lots having a predetermined number of articles. The counter unit includes (1) a first conveyor that delivers a flow of articles separated at intervals, and (2) at least one bin positioned to receive articles from the conveyor. The at least one bin may have first and second outlet gates for emptying the articles into first and second separate locations. A detector unit counts the articles that are received from the conveyor into the at least one bin and which fall within the predetermined size range. A control unit causes the first outlet gate to open when the count of articles is equal to the predetermined number of articles. However, when an article falls outside the predetermined size range, the detector generates an out-of-size signal. The control unit, upon receipt of the out-of-size signal from the detector unit, causes the second outlet gate to open, thereby rejecting the articles. The counter unit may also be used for counting articles having a predetermined color into lots having a predetermined number of articles. When an article does not have the predetermined color, the detector generates an out-of-color signal. The control unit, upon receipt of the out-of-color signal from the detector unit, causes the second outlet gate to open, thereby rejecting the articles.
The counter unit of the aforementioned U.S. Pat. No. 6,563,901 B2 is quick and efficient. However, in certain applications, as non-limiting examples, in packaging of pharmaceutical dosage forms such as pills, capsules, or the like; or of foods such as candies (wrapped or unwrapped) or other mixtures of various ingredients, apportioning the articles by gross volume is more efficient. U.S. Pat. No. 6,799,684 B2, which is incorporated herein by reference in its entirety, discloses an article detecting and counting apparatus which comprises a detector unit which detects and maintains a count of articles that are received in the apparatus or which fall within a predetermined range of a predetermined specification such as volume, a diverter gate which holds and releases batches of articles for further processing, at least two outlet gates for emptying articles from apparatus into respective first and second locations in response to signals from a control unit which determines based on signals from the detector whether or not the count or volume of articles is equal to the predetermined number and/or volume of articles.
Notwithstanding the foregoing improvements in article detection, counting and packaging, the prior art systems are limited in their ability to provide high speed, verified accurate and repeatable batch processing and disposition of acceptable and rejected article batches.
It is, therefore, an object of the present invention to overcome the deficiencies of prior art devices and methods and to provide an apparatus and method for portioning articles that accurately counts a predetermined number of discrete articles, regardless of size and/or shape, and/or dispenses articles that are within predetermined specifications such as total size or volume or color (or combinations of such specifications), at a higher article throughput while maintaining very high levels of accuracy. For convenience in the following description of the present invention, and in particular preferred embodiments thereof, the terms “portioning head” and “counting head” are to be understood as referring to the same concept, i.e., a device which detects and accumulates information regarding articles passing therethrough and determines the number and/or other characteristics of the articles passing through the detector.
It is another object of the present invention to provide an article detecting and portioning apparatus that is relatively simple and inexpensive to manufacture and to maintain, and that is relatively easy to maintain with high levels of cleanliness.
It is a further object of the present invention to provide for continuous accumulation of articles during indexing of the portioning head and/or a container to be filled into and/or out of a fill zone.
It is another object of the present invention to provide a counting apparatus and system which employs fewer article flow control devices such as diverting gates, and substantially reduces and/or eliminates the need for article flow control device position sensors to determine device position and/or jam or fault conditions.
It is another object of the present invention to provide an apparatus and method in which a plurality of counting heads of the aforementioned type are co-located and arranged to provide a high-speed, verified batch filling system for continuous or near-continuous container filling operation.
Consistent with the foregoing objects, the present invention provides an article detecting and counting head apparatus, a multi-head article processing apparatus comprising a plurality of said article detecting and counting head apparatus, and associated methods for operating same. The articles could be essentially any loose articles, such as pieces of candy (wrapped or unwrapped), pharmaceutical products such as tablets, capsules, or any other dosage form which can be subjected to handling, non-consumable products such as pellets used to inflate vehicle airbags or electronic components such as chips, resistors, capacitors, transistors, or the like; or any other type of product to be separated from bulk quantities into individual or multiple package units, as long as they can be handled in bulk and separated into discrete units to, for example, have their volume determined, to be counted, measured and/or weighed, or to be otherwise subjected to measurement of other physical characteristics such as color, shape, or the like, or combinations thereof, such as volume determinations combined with count or color determination.
The counting head apparatus includes a detector unit which detects and maintains a count of articles that are received in the apparatus or which fall within a predetermined range of a predetermined specification such as volume, which detector generates an out-of-specification signal when an article or group of articles received in the apparatus falls outside the predetermined range. The detector is located in or near a chamber positioned to receive articles from a flow of articles delivered to the apparatus. An upper diverting gate is disposed in the chamber, and is arranged to alternately direct articles fed into the chamber into either of two channels within the chamber. The diverting gate position is controlled by a smart gate repositioning device, such as a smart servo motor unit, a smart stepper motor unit or the like, which can provide signals indicating the position of its drive mechanism. For convenience, hereinafter, the term “smart servo motor” is to be understood as referring generally to any gate reposition device, including smart stepper motors and the like.
A lower outlet gate, also controlled by a smart servo motor, alternates between the two channels within the chamber, independent from the diverter gate position, to control the accumulation and release of articles in the counting head. A control unit receives signals from at least the detector unit and the upper diverting gate and lower outlet gate smart servo motors to determine and command the positioning of the diverting and outlet gates and to control the feed rate of articles into the counting head chamber from an article feed device (not illustrated) to optimize counting accuracy and article batch processing speed.
In operation, the counting head apparatus receives articles into the chamber, which are detected as they pass through the detector unit. At the beginning of the accumulation of a batch of articles, the diverting gate is positioned by the smart servo motor to one side or the other of the chamber in order to divert the incoming articles into one of the two channels. For illustrative purposes, in this example the diverting gate is set toward a left side of the chamber, such that the articles are diverted into the right of the two channels. At the same time the outlet gate is positioned to block the outlet of the other channel (the left channel in this example), such that the articles entering the right channel may pass through the chamber to be received in a container, such as a plastic bottle for pharmaceutical tablets or other type of container or packaging. When the detector unit detects the count or volume of articles that have passed through the chamber is equal to the predetermined number and/or the articles fall within the predetermined range of the predetermined volume, the control unit commands the diverting gate to move to block the opposite channel (in this example, from blocking the left channel to blocking the right channel), thereby diverting the flow of articles into the left channel, where they begin to accumulate above the outlet gate. While articles continue to be counted by the detector unit and accumulate in the left channel, a new empty container is positioned below the counting head by indexing the counting head to a position over a new container and/or indexing a new container below the counting head. Once indexing is complete, the control unit commands the outlet gate to move to block the outlet of the other channel (in this example, from blocking the left channel outlet to blocking the right channel outlet), allowing the accumulated articles to drop into the new empty container. If the number or volume of articles accumulated at the time the outlet gate is repositioned is a partial batch, additional articles are allowed to pass through the channel into the container until the detector unit determines a complete batch has passed through the detector and the control unit commands the diverting gate to block the open channel (in this example, the left channel). The alternating partial accumulation process then begins anew with the accumulation of articles in the other channel (in this example, the right channel) while indexing to locate a new container beneath the counting head is completed. The present invention's counting head therefore provides the ability to accumulate and dispense predetermined batches of articles on an continuous, uninterrupted flow basis.
In the event the detector unit determines that the article characteristic being detected (e.g., count, volume, color) is outside the predetermined acceptable range, the accumulated batch is identified as bad. There are various possible approaches available for removing the bad batch from the product packaging stream, such as electronic identification of a container filled with the bad batch for removal from the container filling line downstream from the counting head, or controlling the outlet gate to release the accumulated bad batch at a time when a container is not indexed below the counting head, such that the bad batch passes to a rejected batch accumulation bin, preferably for inspection and/or recycling back into the article feed system.
In a further embodiment of the present invention, a plurality of the aforementioned counting heads are co-located to receive articles from a common supply device, and a continuous supply of containers to be filled are fed into fill positions beneath the counting heads to receive article batches accumulated in the counting heads. In one embodiment of this batch counting system, the plurality of counting heads are mounted on an outer periphery of a carousel-type rotary article feed platform. As the rotary feed platform rotates, a container feed conveyer directs empty containers onto the carousel beneath the counting heads, such that a container is located beneath each counting head for the majority of a revolution of the carousel. As the containers near the completion of a revolution of the carousel, the now-filled containers may be directed off the carousel back onto another conveyer for transport downstream for further processing. The containers are filled in the following manner. As the carousel rotates, a source of articles, such as a vibratory conveyer, feeds articles to the top of the feed platform. The feed platform, which may be shaped as a flat cone, distributes the articles uniformly radially outwards towards the entrances of the plurality of counting heads. The feed rate of the articles and the carousel rotation rate are controlled such that by the time the counting head and its associated container have reached the point of removal of the container from the carousel, a complete batch has been received in the container. Due to the present invention's advantages in supporting continuous counting and accumulation, during the period of carousel rotation when a counting head is not indexed over a container (i.e., between the time a filled container is removed from the carousel and the counting head is rotated around the carousel to meet a new container entering the carousel), articles may continue to be fed into the counting head from the continuous article feed platform. Once indexed above a container, the controller may reposition the counting unit's outlet gate to allow the accumulated articles to fall into the container and permit further articles to fall through the open channel into the container until a complete batch is received and the diverting gate is repositioned to stop filling and begin accumulation in the other channel while the filled container is removed from the carousel. The control unit may also be provided with feedback control in order to control the feed rate of the articles onto the feed platform and/or the carousel rotation speed, such that the counting heads are receiving articles at a rate which optimizes the detector unit accuracy, while also receiving a sufficient amount of articles to complete a batch by the time each counting head reaches a predetermined position around the carousel. Controlling feed rate and carousel rotation speed in this manner ensures the container will receive the complete batch before the container leaves the carousel.
Other multi-head continuous batch filling configurations are also possible. For example, rather than the foregoing rotary carousel counting head and container indexing system, a linear filling station may be constructed, in which a plurality of counting heads are arranged, for example, adjacent to one another. In such a system, a continuous article feed system, such as a bin-fed vibratory feeder, uniformly feeds articles to the tops of each of the counting head chambers. Due to the continuous counting and accumulation capability of the present invention, while the counting heads are accumulating articles, groups of empty containers are advanced along a container conveyer beneath the counting heads, with one container indexed beneath each counting head. When the containers are indexed into their respective fill positions, the control unit may reposition the outlet gate to permit the accumulated articles to fall into the containers and to allow the remaining articles in the batch to pass through the open channel until the batch is complete. Once the detector unit determines the batch is complete and the control unit repositions the diverting gate to block the channel feeding the container, and all the counting head diverting gates are repositioned, the group of filled containers is conveyed downstream and a new group of empty containers is indexed into position beneath the counting heads. The control unit then may reposition the outlet gates to restart the container filling process.
Advantageously, because the counting heads of the present invention employ smart gate repositioning devices, the control unit can readily detect article jamming and other flow control problems by determining that the gates are not in the commanded position. For example, in the event a gate is not completely closed due to accumulated articles jammed between the chamber wall and the gate, the servo or stepper motor position indication would indicate that the gate is not fully closed. The controller therefore can detect errors and react (such as initiating alarms or shutting down filling system operation), without the need for additional, dedicated sensors. In addition, because the smart servo motors allow very fine gate motion control, the gates may be repositioned at very high speed, but decelerated as they near the chamber wall in order to reduce or eliminate the high-speed gate impact with the chamber wall. This feature allows higher continuous counting and filling system operating speeds without exceeding gate and chamber component wear and high operating noise levels from gate/wall impacts. The position indication and associated fine control of the stepper or servo motors also allows for controlled release of articles which have accumulated above an outlet gate, minimizing the potential for clogging of the chamber outlet by sudden release of a large number of accumulated articles. The fine control over gate position permits the outlet gate to be controlled to initially open slowly, so that only a fraction of the accumulated articles begins to fall towards the chamber outlet, to be followed by the rest of the accumulated articles as the gate begins to accelerate towards its new position.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.